/* opcode of machine instruction */
#define  I_END	  0x00
#define  I_NOP    0x01
#define  I_OTC    0x02
#define  I_OTI    0x03
#define  I_OTS    0x04
#define  I_ITC    0x05
#define  I_ITI    0x06
#define  I_LOD_0  0x10
#define  I_LOD_1  0x11
#define  I_LOD_2  0x12
#define  I_LOD_3  0x13
#define  I_LDC_3  0x113
#define  I_LOD_4  0x14
#define  I_LDC_4  0x114
#define  I_LOD_5  0x15
#define  I_LDC_5  0x115
#define  I_STO_0  0x20
#define  I_STC_0  0x120
#define  I_STO_1  0x21
#define  I_STC_1  0x121
#define  I_STO_2  0x22
#define  I_STC_2  0x122
#define  I_STO_3  0x23
#define  I_STC_3  0x123
#define  I_ADD_0  0x30
#define  I_ADD_1  0x31
#define  I_SUB_0  0x40
#define  I_SUB_1  0x41
#define  I_MUL_0  0x50
#define  I_MUL_1  0x51
#define  I_DIV_0  0x60
#define  I_DIV_1  0x61
#define  I_TST_0  0x70
#define  I_JMP_0  0x80
#define  I_JMP_1  0x81
#define  I_JEZ_0  0x82
#define  I_JEZ_1  0x83
#define  I_JLZ_0  0x84
#define  I_JLZ_1  0x85
#define  I_JGZ_0  0x86
#define  I_JGZ_1  0x87
